Eric Lee / smarc-ti-linux-kernel

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Commit 6d4e81ed89c092cb156c8d19cb68c8733cd502b3

Authored by Tomeu Vizoso
Committed by Rafael J. Wysocki
1 parent f41f4815f8
Exists in ti-lsk-linux-4.1.y and in 10 other branches dlt-processor-sdk-linux-03.00.00.04, processor-sdk-linux-02.00.01, smarc-ti-lsk-linux-4.1.y, smarct3x-processor-sdk-04.01.00.06, smarct3x-processor-sdk-linux-02.00.01, smarct3x-processor-sdk-linux-03.00.00.04, smarct4x-800-processor-sdk-linux-02.00.01, smarct4x-processor-sdk-04.01.00.06, smarct4x-processor-sdk-linux-02.00.01, smarct4x-processor-sdk-linux-03.00.00.04

cpufreq: Ref the policy object sooner 

Do it before it's assigned to cpufreq_cpu_data, otherwise when a driver
tries to get the cpu frequency during initialization the policy kobj is
referenced and we get this warning:

------------[ cut here ]------------
WARNING: CPU: 1 PID: 64 at include/linux/kref.h:47 kobject_get+0x64/0x70()
Modules linked in:
CPU: 1 PID: 64 Comm: irq/77-tegra-ac Not tainted 3.18.0-rc4-next-20141114ccu-00050-g3eff942 #326
[<c0016fac>] (unwind_backtrace) from [<c001272c>] (show_stack+0x10/0x14)
[<c001272c>] (show_stack) from [<c06085d8>] (dump_stack+0x98/0xd8)
[<c06085d8>] (dump_stack) from [<c002892c>] (warn_slowpath_common+0x84/0xb4)
[<c002892c>] (warn_slowpath_common) from [<c00289f8>] (warn_slowpath_null+0x1c/0x24)
[<c00289f8>] (warn_slowpath_null) from [<c0220290>] (kobject_get+0x64/0x70)
[<c0220290>] (kobject_get) from [<c03e944c>] (cpufreq_cpu_get+0x88/0xc8)
[<c03e944c>] (cpufreq_cpu_get) from [<c03e9500>] (cpufreq_get+0xc/0x64)
[<c03e9500>] (cpufreq_get) from [<c0285288>] (actmon_thread_isr+0x134/0x198)
[<c0285288>] (actmon_thread_isr) from [<c0069008>] (irq_thread_fn+0x1c/0x40)
[<c0069008>] (irq_thread_fn) from [<c0069324>] (irq_thread+0x134/0x174)
[<c0069324>] (irq_thread) from [<c0040290>] (kthread+0xdc/0xf4)
[<c0040290>] (kthread) from [<c000f4b8>] (ret_from_fork+0x14/0x3c)
---[ end trace b7bd64a81b340c59 ]---

Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Showing 1 changed file with 21 additions and 21 deletions Side-by-side Diff

drivers/cpufreq/cpufreq.c
Diff comments   View file @ 6d4e81e
... ... @@ -900,46 +900,31 @@
900 900 struct freq_attr **drv_attr;
901 901 int ret = 0;
902 902  
903   - /* prepare interface data */
904   - ret = kobject_init_and_add(&policy->kobj, &ktype_cpufreq,
905   - &dev->kobj, "cpufreq");
906   - if (ret)
907   - return ret;
908   -
909 903 /* set up files for this cpu device */
910 904 drv_attr = cpufreq_driver->attr;
911 905 while ((drv_attr) && (*drv_attr)) {
912 906 ret = sysfs_create_file(&policy->kobj, &((*drv_attr)->attr));
913 907 if (ret)
914   - goto err_out_kobj_put;
  908 + return ret;
915 909 drv_attr++;
916 910 }
917 911 if (cpufreq_driver->get) {
918 912 ret = sysfs_create_file(&policy->kobj, &cpuinfo_cur_freq.attr);
919 913 if (ret)
920   - goto err_out_kobj_put;
  914 + return ret;
921 915 }
922 916  
923 917 ret = sysfs_create_file(&policy->kobj, &scaling_cur_freq.attr);
924 918 if (ret)
925   - goto err_out_kobj_put;
  919 + return ret;
926 920  
927 921 if (cpufreq_driver->bios_limit) {
928 922 ret = sysfs_create_file(&policy->kobj, &bios_limit.attr);
929 923 if (ret)
930   - goto err_out_kobj_put;
  924 + return ret;
931 925 }
932 926  
933   - ret = cpufreq_add_dev_symlink(policy);
934   - if (ret)
935   - goto err_out_kobj_put;
936   -
937   - return ret;
938   -
939   -err_out_kobj_put:
940   - kobject_put(&policy->kobj);
941   - wait_for_completion(&policy->kobj_unregister);
942   - return ret;
  927 + return cpufreq_add_dev_symlink(policy);
943 928 }
944 929  
945 930 static void cpufreq_init_policy(struct cpufreq_policy *policy)
... ... @@ -1198,6 +1183,8 @@
1198 1183 goto err_set_policy_cpu;
1199 1184 }
1200 1185  
  1186 + down_write(&policy->rwsem);
  1187 +
1201 1188 /* related cpus should atleast have policy->cpus */
1202 1189 cpumask_or(policy->related_cpus, policy->related_cpus, policy->cpus);
1203 1190  
1204 1191  
... ... @@ -1210,9 +1197,17 @@
1210 1197 if (!recover_policy) {
1211 1198 policy->user_policy.min = policy->min;
1212 1199 policy->user_policy.max = policy->max;
  1200 +
  1201 + /* prepare interface data */
  1202 + ret = kobject_init_and_add(&policy->kobj, &ktype_cpufreq,
  1203 + &dev->kobj, "cpufreq");
  1204 + if (ret) {
  1205 + pr_err("%s: failed to init policy->kobj: %d\n",
  1206 + __func__, ret);
  1207 + goto err_init_policy_kobj;
  1208 + }
1213 1209 }
1214 1210  
1215   - down_write(&policy->rwsem);
1216 1211 write_lock_irqsave(&cpufreq_driver_lock, flags);
1217 1212 for_each_cpu(j, policy->cpus)
1218 1213 per_cpu(cpufreq_cpu_data, j) = policy;
... ... @@ -1303,6 +1298,11 @@
1303 1298 per_cpu(cpufreq_cpu_data, j) = NULL;
1304 1299 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
1305 1300  
  1301 + if (!recover_policy) {
  1302 + kobject_put(&policy->kobj);
  1303 + wait_for_completion(&policy->kobj_unregister);
  1304 + }
  1305 +err_init_policy_kobj:
1306 1306 up_write(&policy->rwsem);
1307 1307  
1308 1308 if (cpufreq_driver->exit)